package com.json2bean.test;

/**
 * json格式化工具
 * @author Young
 *
 */
public class JsonFormat {

	/**
	 * 默认每次缩进两个空格
	 */
	private static final String empty="  ";

	public static String format(String json){
		try {
			json=removeUnUsedSpaces(json);
			int empty=0;
			char[]chs=json.toCharArray();
			StringBuilder stringBuilder=new StringBuilder();
			for (int i = 0; i < chs.length;) {
				//若是双引号，则为字符串，下面if语句会处理该字符串
				if (chs[i]=='\"') {
					
					stringBuilder.append(chs[i]);
					i++;
					//查找字符串结束位置
					for ( ; i < chs.length;) {
						//如果当前字符是双引号，且前面有连续的偶数个\，说明字符串结束
						if ( chs[i]=='\"'&&isDoubleSerialBackslash(chs,i-1)) {
							stringBuilder.append(chs[i]);
							i++;
							break;
						} else{
							stringBuilder.append(chs[i]);
							i++;
						}
						
					}
				}else if (chs[i]==',') {
					stringBuilder.append(',').append('\n').append(getEmpty(empty));
					
					i++;
				}else if (chs[i]=='{'||chs[i]=='[') {
					empty++;
					stringBuilder.append(chs[i]).append('\n').append(getEmpty(empty));
					
					i++;
				}else if (chs[i]=='}'||chs[i]==']') {
					empty--;
					stringBuilder.append('\n').append(getEmpty(empty)).append(chs[i]);
					
					i++;
				}else {
					stringBuilder.append(chs[i]);
					i++;
				}
				
				
			}
			

			
			return stringBuilder.toString();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return json;
		}
		
	}
	private static boolean isDoubleSerialBackslash(char[] chs, int i) {
		int count=0;
		for (int j = i; j >-1; j--) {
			if (chs[j]=='\\') {
				count++;
			}else{
				return count%2==0;
			}
		}
		
		return count%2==0;
	}
	/**
	 * 缩进 
	 * @param count
	 * @return
	 */
	private static String getEmpty(int count){
		StringBuilder stringBuilder=new StringBuilder();
		for (int i = 0; i < count; i++) {
			stringBuilder.append(empty) ;
		}
		
		return stringBuilder.toString();
	}


	private static String removeUnUsedSpaces(String json){
		char[]chs=json.toCharArray();
		StringBuilder stringBuilder=new StringBuilder();
		for (int i = 0; i < chs.length;) {
			//若是双引号，则为字符串，下面if语句会处理该字符串
			if (chs[i]=='\"') {
				
				stringBuilder.append(chs[i]);
				i++;
				//查找字符串结束位置
				for ( ; i < chs.length;) {
					//如果当前字符是双引号，且前面有连续的偶数个\，说明字符串结束
					if ( chs[i]=='\"'&&isDoubleSerialBackslash(chs,i-1)) {
						stringBuilder.append(chs[i]);
						i++;
						break;
					} else{
						stringBuilder.append(chs[i]);
						i++;
					}
					
				}	
			}else{
				
				if (chs[i]==' '||chs[i]=='\t'||chs[i]=='\n') {
					i++;
					continue;
				}
				
				stringBuilder.append(chs[i]);
				i++;
			}
			
		}
		
		return stringBuilder.toString();
	}

}
  